1. Field of the Invention
This invention relates generally to a method and apparatus for a specially processed fiber to distribute energy to a medium in which the fiber is embedded. More particularly, this invention relates to a processed fiber embedded in a sealant material that is capable of propagating excess energy through the sealant material without substantial absorption.
2. Description of the Art
Sealant materials are used to repair structure parts of aircraft such as helicopters, by adhering parts that require repair. The sealant material interacts with the structure and can adhere broken portions or seal cracks. Unfortunately, conventional sealant materials used to repair aircraft parts require extended periods of time to adequately cure. This removes the aircraft from active flight status for several hours. Curing the sealant material can be enhanced by using an external source of thermal energy, such as a heating blanket. However, since the sealant material may have poor thermal conductivity, there may be unbalanced curing of the material. For example, a portion of the sealant material in close proximity to the heat source may be over-cured, while a portion of the sealant more remote from the heat source may remain essentially uncured. Thus, the physical properties of the sealant materials necessitate extended cure times causing an aircraft to be removed from active status while the sealant cures.
A second drawback to curing processes that utilize conventional external heat sources is that these heat sources are typically bulky and cumbersome. Application of an external heat source may require removal of components and/or cargo from the aircraft to enable access for the repair operation. Furthermore, the use of a bulky heat source makes access to small areas difficult. Additionally, thermal blankets and electric heat sources may spark and are therefore a fire hazard.
For thick repair regions, the poor thermal conductivity of the sealant material could preclude proper heating of the repair sealant. In order to adequately cure the entire sealant volume, the additional heat often results in over heating, and weakening, of the surrounding regions.
Separately, U.S. Pat. No. 5,770,296 discloses an adhesive device that absorbs electromagnetic waves contiguous with a heat-activatable adhesive material. This reference does not solve the problem of efficient curing because a portion of the adhesive material closest to the heat energy will cure before a portion of adhesive material further from the heat source. This reference is hereby incorporated by reference. Furthermore, this reference does not relate to aircraft or repairing parts on aircraft. Therefore, what is needed to streamline aircraft and other structure repair is a process for repairing damage that is time efficient and does not introduce the unnecessary risk of spark that is present with electric heating blankets. Fibers, such as optical fibers, typically provide a conduit for signals or energy to be transmitted to a destination location, which is usually at a terminal end of the fiber. However, it has been discovered that processing a fiber and embedding the processed fiber in a medium permits energy to be distributed along the length of the fiber and absorbed by the medium generally uniformly. Specifically, embedding processed fibers in a curable sealant material facilitates rapid uniform cure of the sealant.